1. Field of the Invention
The present invention generally relates to medical devices, methods, and systems. More specifically, the present invention provides techniques for selectively heating and shrinking tissues, particularly for the noninvasive treatment of urinary incontinence and hernias, for cosmetic surgery, and the like.
Urinary incontinence arises in both women and men with varying degrees of severity, and from different causes. In men, the condition occurs almost exclusively as a result of prostatectomies which result in mechanical damage to the sphincter. In women, the condition typically arises after pregnancy where musculoskeletal damage has occurred as a result of inelastic stretching of the structures which support the genitourinary tract. Specifically, pregnancy can result in inelastic stretching of the pelvic floor, the external sphincter, and most often, to the tissue structures which support the bladder and bladder neck region. In each of these cases, urinary leakage typically occurs when a patient""s intra-abdominal pressure increases as a result of stress, e.g. coughing, sneezing, laughing, exercise, or the like.
Treatment of urinary incontinence can take a variety of forms. Most simply, the patient can wear absorptive devices or clothing, which is often sufficient for minor leakage events. Alternatively or additionally, patients may undertake exercises intended to strengthen the muscles in the pelvic region, or may attempt behavior modification intended to reduce the incidence of urinary leakage.
In cases where such noninterventional approaches are inadequate or unacceptable, the patient may undergo surgery to correct the problem. A variety of procedures have been developed to correct urinary incontinence in women. Several of these procedures are specifically intended to support the bladder neck region. For example, sutures, straps, or other artificial structures are often looped around the bladder neck and affixed to the pelvis, the endopelvic fascia, the ligaments which support the bladder, or the like. Other procedures involve surgical injections of bulking agents, inflatable balloons, or other elements to mechanically support the bladder neck.
Each of these procedures has associated shortcomings. Surgical operations which involve suturing of the tissue structures supporting the urethra or bladder neck region require great skill and care to achieve the proper level of artificial support. In other words, it is necessary to occlude or support the tissues sufficiently to inhibit urinary leakage, but not so much that intentional voiding is made difficult or impossible. Balloons and other bulking agents which have been inserted can migrate or be absorbed by the body. The presence of such inserts can also be a source of urinary tract infections. Therefore, it would be desirable to provide an improved therapy for urinary incontinence.
A variety of other problems can arise when the support tissues of the body have excessive length. Excessive length of the pelvic support tissues (particularly the ligaments and fascia of the pelvic area) can lead to a variety of ailments including, for example, cystocele, in which a portion of the bladder protrudes into the vagina. Excessive length of the tissues supporting the breast may cause the breasts to sag. Many hernias are the result of a strained, tom, and/or distended containing tissue, which allows some other tissue or organ to protrude beyond its contained position. Cosmetic surgeries are also often performed to decrease the length of support tissues. For example abdominoplasty (often called a xe2x80x9ctummy tuckxe2x80x9d) is often performed to decrease the circumference of the abdominal wall. The distortion of these support tissues may be due to strain, advanced age, congenital predisposition, or the like.
Unfortunately, many support tissues are difficult to access, and their tough, fibrous nature can complicate their repair. As a result, the therapies now used to improve or enhance the support provided by the ligaments and fascia of the body often involve quite invasive surgical procedures.
For these reasons, it would be desirable to provide improved devices, methods, and systems for treating fascia, tendons, and the other support tissues of the body. It would be particularly desirable to provide improved noninvasive or minimally invasive therapies for these support tissues, especially for the treatment of urinary incontinence in men and women. It would further be desirable to provide treatment methods which made use of the existing support structures of the body, rather than depending on the specific length of an artificial support structure.
2. Description of the Background Art
U.S. Pat. No. 5,423,811 describes a method for RF ablation using a cooled electrode. U.S. Pat. Nos. 5,458,596 and 5,569,242 describe methods and an apparatus for controlled contraction of soft tissue. An RF apparatus for controlled depth ablation of soft tissue is described in U.S. Pat. No. 5,514,130.
U.S. Pat. No. 4,679,561 describes an implantable apparatus for localized heating of tissue, while U.S. Pat. No. 4,765,331 describes an electrosurgical device with a treatment arc of less than 360 degrees. An impedance and temperature generator control is described in U.S. Pat. No. 5,496,312. Bipolar surgical devices are described in U.S. Pat. Nos. 5,282,799, 5,201,732, and 728,883.
In a first aspect, the present invention provides a probe comprising a first electrode having a first electrode surface with a first edge. A second electrode has a second electrode surface with a second edge adjacent the first edge. The first and second surfaces are aligned so as to simultaneously engage a tissue surface. An insulator is disposed between the first and second electrode. The insulator extends beyond the edges so as to avoid edge induced concentration of current flux. The insulator will typically comprise a protruding rib or a film.
In a second aspect, the present invention provides a probe comprising a first electrode having a first electrode surface for engaging a tissue surface of a tissue. A second electrode has a second electrode surface which is oriented to engage the tissue surface simultaneously with the first electrode surface. A rib between the first and second electrodes extends beyond the electrode surfaces so as to protrude into the tissue.
The rib will generally be electrically isolated from the first and second electrodes, so that the rib can direct a bi-polar current flux between the electrode surfaces into the tissue beyond the protruding rib. The rib may be adapted to distend the tissue surface (for example, by providing a rounded protruded edge, or by forming the rib from a soft material), or may instead be adapted to incise the tissue surface (for example, by forming the rib with a sharp and/or hard protruding edge). Preferably, a cooling system will be coupled to the first and second electrodes for cooling the engaged tissue surface.
The ribbed probe of the present invention is particularly well adapted for directing current flux through an intermediate tissue and into a collagenous target tissue so as to heat and shrink the collagenous tissue. Cooling of the electrode surfaces can help minimize collateral damage to the intermediate tissue during this process.
In another aspect, the invention provides a probe comprising first and second electrically and thermally conductive tubes. Each of the tubes has an electrode surface and a side surface with an edge therebetween. An electrical insulation film is disposed between the side surfaces of the tubes. The film is thermally conductive and has an exposed cooling surface extending between the electrode surfaces of the tubes, and cooling surface being thermally coupled to a cooling fluid.
Advantageously, the film can avoid electrical current concentrations (and localized overheating) at the edges of the electrode surfaces, while applying cooling contiguously across a pair of separated bipolar electrodes.